Various types of locating and navigation systems for vehicles are known. Road maps, for example city maps, are stored on compact discs. The instantaneous position of a vehicle is indicated on a monitor, by coupling the information in the compact disc to a vehicle position in computer apparatus. Storing detailed street maps of cities requires a large memory capacity. To record or input a particular travel route of a vehicle on a street map displayed on a monitor requires substantial circuitry and equipment, since the travel route of the vehicle must be entered point-by-point.
German Patent Disclosure Document DE-OS 38 06 842, KNOLL, describes an arrangement to simplify the inputting of information by carrying out input of a travel route with help of a digitized table. A street map of a city is placed beneath a transparent digitized pad, and the desired route is then scanned by a digitizing wand which transfers the desired route point-by-point to a data memory. A system of this kind requires high memory capacity which, particularly on longer trips, may rise rapidly. The stored quantity of data also requires excessive calculating time upon switching from a section of a street map, for example, to another part of the city and to another street map, or due to change of the scale of the map.
The output derived from the navigation system for vehicle travel information could be the straight line or air line distance, and direction to the target point, or the position of the vehicle on the route, and its direction of movement. The output, however, does not provide a street map in which the route is clearly shown and readily recognized, and which facilitates orientation in the city for the operator.